Hello, On Saturday 17 January 2009 15:29, Eric Kow wrote: > Refactor add_to_list. > --------------------- > > +-- | Add element @x@ to list @xs@ if it isn't there yet. > > add_to_list :: Eq a => a -> [a] -> [a] > > hunk ./src/Darcs/Repository/Prefs.lhs 382 > > -add_to_list s [] = [s] > > -add_to_list s (s':ss) = if s == s' then (s:ss) else s': add_to_list s ss > > +add_to_list x xs = if x `elem` xs then xs else x : xs > > Does it matter that x is now added to the front of the list instead of > to the back? (I guess we could do xs ++ [x] if it does indeed matter)
That would cause the list to be traversed twice. > > -- > Eric Kow <http://www.nltg.brighton.ac.uk/home/Eric.Kow> > PGP Key ID: 08AC04F9 > Best regards Thorkil _______________________________________________ darcs-users mailing list [email protected] http://lists.osuosl.org/mailman/listinfo/darcs-users
